Three weeks after his unexpected demise, the flurry of stories emerging about Michael Jackson's life and death have grown into a bizarre soap opera, resembling a cross between Twin Peaks and Dynasty. The past 24 hours alone have seen claims that he was murdered and appeared as a ghost on a car bonnet, plus new tales emerging about the cause and extent of his drug addiction, and further speculation over the fate of his children. Even Jackie Collins or Trey Parker and Matt Stone would have trouble weaving together so seemingly improbable a narrative.

Perhaps the most dramatic new revelation is the release of never-before seen footage of Jackson's head catching on fire during the filming of his Pepsi commercial on 27 January 1984. Photographs of the accident that left him with second and third degree burns to his face and scalp have been seen before. But the video, obtained by Us Weekly magazine, shows the moment Jackson's hair caught fire and the severity of the burns he suffered.

The pop star is seen rehearsing his hit song Billie Jean on stage at Los Angeles' Shrine Auditorium. On the sixth take, the fireworks meant to explode behind him go off too early, setting fire to his hair. Jackson at first appears unaware his head is alight. People on the set tackle him to extinguish the flames. When he emerges, the top of his head is bald.

Jackson's injuries have been blamed for his subsequent addiction to painkillers – the severity of which has also been revealed in newly released photographs, which show his lower body bruised and covered in needle marks. A doctor interviewed on ABC News said there could be no legitimate medical reason for the gruesome marks, suggesting the singer was so desperate for drugs he was either injecting himself or being injected by someone else.

The disturbing images emerged as the TMZ website reported that LA police have concluded Jackson's early death might add up to murder after all. According to the gossip website, which broke the news of his death, officers believe Jackson was killed by an anaesthetic, Propofol, which is so powerful it should only be used in hospitals under very controlled conditions, with heart monitoring. LAPD sources told TMZ that statements made by Jackson's personal doctor, Conrad Murray, to police on the Saturday following the star's death contained "incriminating disclosures about his involvement".